Other important soil characteristics are structure (content of stone fragments, hardpan layers, etc), pH (acidity), and nutrient content. Vines often need deep roots, so hardpan layers need to be broken up with deep ripping. Soil pH should be 6.0 to 6.8 for optimal uptake of nutrients. Organic matter should be modest, 2% to 3%, to avoid too much vegetal growth. Grape vines don’t like wet feet, so also important is good drainage, a factor of both texture and slope.
Saanich has had a complex geological history since the last ice age, and therefore has a wide variety of soil materials: glacial till soils of mixed textures, beach/alluvial soils of medium to coarse textures, and marine clay soils of medium to fine textures. Saanich soil pH is often too low (too acidic) and needs to be raised by adding lime for several years.
Symphony’s vineyard site on Oldfield Rd consists primarily of a rocky glacial till loam. Our steady slope provides excellent drainage, which allows the soil to dry out and warm up relatively quickly during the summer. We deep-ripped before planting to break up occasional clay layers, and added lime for several years to adjust the soil pH. Every couple of years we have the soil analyzed to help plan our fertilizer program. We maintain a custom-mix grass cover crop between the rows to reduce soil erosion and compaction, improve the soil structure with organic matter, and promote soil flora and fauna.
As you can see, BC wineries are near the edge of the northern viticulture zone. Our own growing area is located near the ocean, which of course strongly moderates both our summer and winter temperatures relative to further-inland continental wine areas like the Okanagan. We also have a radically different rainfall pattern than the Okanagan – they have very little precipitation during the winter and start the growing year with very dry soils, while our wet winters mean we start with completely saturated soils.
Other important climate variables for successful winegrape growing are the amount of summer rainfall, the frost risk at each end of the growing season (April to October), and especially, the accumulated heat during the growing season, usually measured in Growing Degree Days (GDD). To obtain GDD, the average temperature above 10°C is calculated each day and cumulatively added up during the growing season, as illustrated below for two consecutive days which sum up to 9 GDD:
Growing Degree Days allow us to compare one year to others in our area, and to compare ourselves to other winegrape growing areas. Familiarity with the GDD concept will help you understand our monthly updates under the Saanich Climate tab.
Different winegrape varietals require different amounts of heat (GDD) to ripen, and it’s very important to plant grape varietals which are matched to your climate. A quickly ripening varietal planted in a hot climate will ripen during the hot summer, which is too soon – many of the wonderful complex aromas and flavours in wine develop during the fall, when the nights are cool and the leaves are beginning to turn. Conversely, a slowly ripening varietal in a cool climate won’t ripen at all.
Saanich is definitely a cool-climate viticulture region, and requires early ripening varietals. Our climate is perfect for crisp, aromatic whites such as Symphony’s Gewürztraminer, Pinot Gris, and Ortega; although our summers are relatively cool, there’s very little frost risk in the fall and we can leave the grapes hanging long enough to build up wonderful varietal flavours and aromas. Relatively few of the famous red grapes will fully ripen here; in a good year Pinot Noir can produce wonderful Burgundy-style reds, while in cooler years the same grapes can be used for lovely crisp dry Rosés or even whites like Symphony’s Blanc de Noir. At Symphony’s Oldfield Road and Starling Lane vineyards we have Maréchel Foch and Léon Millot, two French-American hybrids created in Colmar, Alsace in the early 1900’s (see our Grapes tab). Due to their partial parentage in quickly-developing American cultivars, Foch and Millot reliably ripen every year in our climate, and produce rich, fruit-forward medium bodied red wines.
Global warming will slowly increase the average heat in our growing seasons. In the medium term, however, the primary climatic factors we have to deal with are large GDD variation from year to year, and large yield variations tied to spring-time temperatures. Our growing season GDD often vary by 15% to 20% from one year to the next, which really drives home the point of planting suitable varietals which ripen regardless of the type of summer we’ve had. Grape harvest yields vary even more, from low crop years like 2012, to record harvests like 2014 in which all six of our varietals yielded 2 to 3 times the amounts in 2012!! The yield is not primarily connected to summertime heat, but rather to the springtime from bud-break (when cluster size is being set) to bloom (when fruit set occurs), and even to springtime of the previous year when the number of clusters for the present year is set. When conditions are perfect for all of these very temperature-sensitive processes, an amazing harvest results, as in 2014.
To help visualize the climate data, we produce the three graphs cycling above these tabs (click on the small circles to freeze one). The first graph shows both the monthly rainfall and GDD (Growing Degree Days, a measure of accumulated heat during the month) going back to 2004; the second shows the cumulative GDD curves back to 2006, and the third shows daily rainfall and high temperatures for the present year.
Lamont has plotted up the data for Saanich through end of 2015 and the growing season GDD curves continued their spectacular trajectories well above all previous years then flattened off as we got into later September. We picked Ortega early September after the heavy rains and following a few sunny days allowing them to dry out. The fruit came in with good ripeness and in great condition. Our Millot then Foch followed mid September, and then our Gewurztraminer followed by Gris, and we finished harvest with our Pinot Noir the week before Thanksgiving.
Monthly GDD and Rainfall
After very warm and dry conditions until late August, September was significantly cooler than average, and for Saanich & Cowichan, somewhat wetter than average also.
October, although probably not that important for most of you with this year’s early harvest, was warmer than average and much drier than last year.
Daily Highs and Rainfall
Around Aug 28, summer seemed to come to an end with the sudden onset of cooler and wetter weather. In Saanich and Cowichan, that was the start of about 10 wet days in a row, putting significant disease pressure on some varietals if spray programs had been less than thorough during the critical bloom and post-bloom periods. There was some rain in the rest of Sep and into Oct, but still plenty of good dry harvest days
Cumulative GDD 2006-2015
Although things cooled off in Sep, 2015 was still the warmest growing season we’ve recorded, and much of the heat came in earlier months when the days were long so I’d imagine the sunshine hours were a record also. The unusually high GDDs this year were due to a warm temperature anomaly in the Pacific off our coast (referred to by oceanographers as the ‘blob’) and not directly to the powerful El Nino now in place. And although this ‘blob’ was a relatively local effect, it looks like 2015 will be the hottest year ever measured globally, as climate change continues its inexorable and extremely dangerous trend.
Long Range Forecast
The combination of the ‘blob’ and El Nino continue to lead to warmer than average 3-month forecasts for the west coast. The strong El Nino is predicted to last into next spring.
The most unusual months of the growing season were May and June, which had very little rainfall and were much warmer than usual, June in particular. It seems like this would have led to much higher irrigation requirements, although surprisingly that wasn’t the case in our own 4 vineyards. 2015, like 2014, had very high harvest yields compared to previous averages, and with the very warm spring we had, 2016 should have a very good cluster count. Are these last couple of years the ‘new normal’, or will we get back to low temperature low yield years like 2010 or 2012??